Antifriction pressure stop for lathes and the like



Nov. 25, 1952 K. FELLROTH 2,618,997

ANTIFRICTION PRESSURE STOP FOR LATHES. AND THE LIKE Filed Feb. 5 1951 FIG4 A i: "f

-lg- E 46444845 i 6| 5o 2o 27 28 le V////////` 6 l I6 a i 2 i FIG 7 INVENToR. l5 52|'4362 53 vKARL FELLROTH 4o 42 59 |60 lm--l-ll 49, /fg 23 X 7 62 ATTORNEY Patented Nov. 25, 1952 UNITED STATES PATENT OFFICE ANTIFRICTION PRESSURE STOP FOR LATHES AND THE LIKE My present invention relates to an attachment for lathes, screw machines and the like in the form of an anti-friction pressure stop for lathes and the like.

It is well known that in ordinary shop practice, when a bar stock projects beyond a certain distance from a chuck or a collet holding the same with its inner end impinging an adjustable stop, that determines the length of a section of the bar to be machined, the bar stock starts to wobble, and when the pressure of a cutting tool, either for surface turning or form tool work, is put against the bar stock, it will chatter and jump and thus make it impossible to do accurate work. Therefore, it becomes necessary to do the turning close to the chuck or collet. At the completion of the turning of the end portion of the bar stock adjacent the chuck or collet, the compound is adjusted to a position in which a cutting tool held thereby is a predetermined distance..`

from the stop and the respective end section of the bar cut-olf. The cut-01T end section of the bar is next turned end for end and placed in the chuck or collet, after the bar stock held in the chuck or collet has been retracted. Next,` i

the stop is adjusted into engagement with the outer end of the cut-off section of the bar, and, nally, the cut-off section of the bar adjacent to the chuck or collet is machined and thereafter removed from the chuck or collet. It will thus be seen that a large number of adjustments must be made for each section of the bar stock j machined and cut off, which consumes a large amount of time and possible error in making A further object of this invention is to provide,V

novel rollers, associated with the bar stock stop,y for positioning and holding a bar stock concentric to the projected axis of the bar stop and for preventing the bar stock from being forced out of true by the pressure of a cutting tool thereagainst, whereby a bar stock may be successivelyl endwise positioned for duplicate sections of a determined length, completely machined and cut off Without changing the adjustment or position of the bar stock stop or the stop of the cut-ofi tool.

Other objects of the invention will be apparent from the following description, reference being had to the drawing.

To the above end, generally stated, the invention consists of the novel devices and corn- 1 bination of devices hereinafter described and dened in the claims.

In the accompanying drawing, which illustrates the invention, like characters indicate like parts throughout the several views.

Referring to the drawing:

Fig. 1 is a front elevational view ci a turret lathe having my improved tool attached thereto;

Fig. 2 is a front elevational view of the improved tool, full size;

Fig. 3 is a right-side elevational view of the same;

Fig. 4 is a view principally in section taken on the line 4 4 of Fig. 2;

Fig. 5 is a view partly in front elevation and partly in transverse vertical section;

Fig. 6 is a fragmentary detail view in plan; and

Fig. 7 is a fragmentary detail view partly in side elevation and partly in section taken on the irregular line 'I-'I of Fig. 6.

For the purpose of showing my improved tool applied in working position, there is shown in Fig. 1 of the drawing a turret lathe indicated as an entirety by the numeral 9 with the exception of the headstock I0, the collet II, the turret I2, the compound I3 and the bar stock feed I4.

Referring now in detail to the improved tool A, the numeral I5 indicates a horizontally disposed body member. This body member I5 has on its right-hand side and bottom an integral semi-cylindrical lateral extension I6. The backs of the body member I5 and its extension are at and flush. The body extension I6 isonly substantially one-half as long as the body member I5. Both fronts of the body member I5 and its extension IB are flat and parallel to the backs thereof. The perimeter of the top and the lefthand side of the body member I5 is a section of a hexagon having its axis coincident with the axis of the body extension I6.

Extending axially into the body member I5 and its extension IS, from the backs thereof, is a bore Il of large diameter. This bore II extends to an internal annular flange I3 at the front of the body extension Ii. The passageway through the flange I8 is designated by the numeral I9. The under side of the body member I5 is transversely concave, as indicated at 20, to aiord clearance forwardly of the body extension I6 to the passageway I9.

A cylindrical head 2I on the outer end of a cylindrical shank 22 extends into the bore I1 from the back of the tool A with a tight t.

This head 2|, at its front end, impinges thel inner side of the flange I8 as a stop, and the rear end portion of said head extends materially rearwardly of the tool A. A set-screw 23 having a socket head has threaded engagement with the body extension I6, impinges the head 2l and holds the same in the bore I1. Within the head 2| is a cylinder 24 of different diameters to aiord an outer annular stop shoulder 25 and an inner annular stop shoulder 26 of a smaller diameter.

A rotatable disk-like stop 21 in the cylinder 24 extends outwardly through the passageway I3 with a working flt and has on its inner end an annular external stop bead 23. 'his'beadllv is on the inner side of the flange I8 and prevents outward movement of the stop 21 through the passageway I9. Integral with the inner end of the stop 21, in axial alignment therewith, Vis a cylindrical shank 29, the axis of which is coincident with the axis of the cylinder 24.

A radial ball bearing 39 supports the shank 29 and hence the stop 21 inthe cylinder 24 for free rotation in the head 2`I. The inner ball race 3I of thebearing 30'is tightly fitted on the shank 29 and againstthe inner end' ofthe vstop 21. The outer ball race 32' of the bearing 33 is tightly fitted in the cylinder 24 and held between the shoulder 25 and thebead 23. The shank 29, rearwardly of the bearing 3,.is reduced in diameter to afford a shoulder 33 andi a thrustA ball Vbearing 34 is mounted on this reduced portion of the shank 29. The bearing 34. is held between the shoulders 25 and 33 and the shoulder 23' affords a base of resistance againstrpress'ure on the stop 21 and transmitted through said stop, the shank 29 and the thrust' bearing 34 to the shoulder 26 on the head2 I. The shank 29 rearwardly of the thrustv bearing 34 is further reduced in diameter to afford a shoulder 35. A stop collar 35 on the reduced rear end portion of the shank 29l engages the shoulder 35 and holdsl theball bearing assembly on the sha-nk 29' when removed from the head 2 I. A set-screw 31'having threaded engagement with the collar 36 impinges the shank 29 and holds said collar on the shank 23.

Extending axially through the shank 22 from its outer4 end to the cylinder 24 isV an oil'. duct 38 for supplying oil to the ball bearing assembly and the stop 21. A screw plug 39 normally closes the Youter end of the vduct 38.'

In the Vfront ofthe body member I5 is a Vertical way 4] abovev the sto'p 21 and a horizontal way- 4I at the left of said stop. Each way 40-4I i'svfa wide shallow channel. A roller slidey 42 is mounted in each way 43-41 and a roller 43 is mounted on the inner end portion of each of said slides." Each roller 43 is journaled on a shaft 4lgwhich, at its inner end portion, extends into a transverse hole in the slide 42, projects outwardly thereof and is secured'to said slide'by apin 45. Heads 46 on the outer ends of the shafts 44 are countersunk in the outer ends of the rollers 43- and hold'the same against removal from the shafts 44. On the inner en-d of each roller 43 is a cylindrical extension 41 of reduced diameter and journaled in the respective slide 42. The transverse center of the Way 4 3 and the axis of theA respective roller 43 are on a vertical line radiating from the center of the stop 21 Vand the transverse center of the way4 4I and the axis of the respective roller 43 are on a horizontal line radiating from the center of said stop. The axis of the shafts 44 and hence the coincident' axes of the rollers 43 are parallel to the axis of the stop 21 and its shank 23. Ball bearings 48 are interposed between the inner 4 ends of the cylindrical extensions 41 and the body member I5.

The slides 42 are each locked in the respective way 40-4I, where adjusted, by a screw 49 that extends through a transverse hole 50 in said slide and a slot 5I in the head I5 that extends longitudinally of the respective Way 43-4I at the transverse center thereof. The screws 49 have heads 52 countersunk in the faces ofthe slides 42 and said screws each has at its inner end portion screw-threaded engagement with a square nut 53 in a long passageway 54 in the body member I5. The passageways 54 are rectangular in cross-section, directly back of the ways 43-4I and parallel thereto, and extend completely through the body member I5. The nuts 53 have asliding working t in the passageways 54 and are held thereby from turning. Obviously, when the screws 49 are tightened, they frictionally clamp the slides onto the bottoms of the ways 43-4 I and holdthe same where adjusted insaid ways.

Each slide 42'is1 moved endwise in the way 4-4I to adjust its roller 43 toward or from the projected axis of the stop 21 and its shank 29 by an adjusting screw 55. This adjusting screw 55 is at one side of the slide 42 and back of the same and has threaded engagement withvthe body member I5. On the adjusting screwr55, at the inner end of its head 55 is an armular lockk flange 51 that extends into a lock notch 58 in the slide 42 and thus separably connects-the adjusting screw 55 to said slide. The head 55? and the lock flange 51 work in a deep hole in the body member I5. The screw head 56V has a nick for a screw driver by means of which the screw 55 may be turned. y

Referring again to the rollers- 43, itis important to note that the inner end portion of each roller 43 has a constant diameter or, in other words, the periphery of the roller is transversely parallel to its axis, as indicated at` 613. Outwardly of this inner end portion of the roller 43, the main body portion thereof is outwardly tapered, as indicated at 6 I. The outer end portion of the roller 43 is rounded as indicated at 62.

In Fig. l of the drawing, the improved tool A is shown as an attachment applied tothe turret I2 with the axis of its stop 21 andshank: 2,9l

for rotation therewith. Obviously, the rotation.

of the bar stock X, in turn. rotates the stopA 21.

When adjusting the rollers` 43 to receive the bar stock X, they are positioned with their lsurfaces 60 the exact dlstancefrom the center of the stop 21 as the radius of aid bar. In endwise .moving the bar stock X to the stop 21, it freely passes the rounded ends 62 of the rollers 43 and engages the tapered surfaces SI o f said roller and is directed thereby onto the roller surfaces 53 and centers the bar stock X with the stop 21.

The cylindrical extension 41 on the rollers 43, that are journaled in the slides 42 with a smooth running t, prevent the rollersV 43 from being forced out of alignment with the projected axis of the stop 21 and its shank 29 by an impact onl said rollers 43 by the bar stock X.

When necessary for some types of machneaa tapered shank for the head 2I may be substituted forA the cylindrical shank 22 shown.

From the above description of my improved tool, it will be seen that after the stop 2l is once set for a section of a bar stock of a predetermined length to be cut therefrom and a second stop set for the compound I3 to position a cut-01T tool held thereby to cut said section, the bar section may be completely machined not only at the end portion held by the chuck or collet, but at the end portion of said bar stock adjacent to the stop 'i and the rollers 3 before the respective section of the bar stock is cut off. It will be seen that after the stops are once set, a number of sections of the bar stock may be endwise positioned, machined and cut off without disturbing the original adjustment of the stops, thus saving a great deal of time, and doing more accurate work.

The drawings illustrate a commercial form of the invention, but it will be understood that the same is capable of certain modifications as to details of construction, arrangement and combination of parts within the scope of the invention herein claimed.

What I claim is:

1. A tool of the class described, a body member having a lateral extension spaced inwardly from the face of the body member, a bore extending into the body member and its extension, said body member and its extension having an internal annular stop flange extending into the bore at the outer end thereof, a head extending into the bore from the rear end thereof and engaging the flange as a stop, means securing the head in the bore, a shank on the head extending rearwardly therefrom, said head having therein a cylinder open at its outer end, a rotatable disk-like stop in said cylinder and extending outwardly through the passageway formed by the annular ange, a bead on the stop, en-

gagoable with the inner side of the ange as a stop, the disk-like stop having on its inner side a shank axially aligned therewith and extending axially in the cylinder, a radial ball bearing supporting the disk-like stop and its shank in the cylinder, and a thrust ball bearing between the shank on the disk-like stop and the head.

2. In a tool of the class described, a body ymember having a bore and an internal annular stop flange extending into the bore at its outer end, a head extending into the bore from its rear end and engaging the flange as a stop, means securing the head in the bore, said head having a rearwardly projecting shank and also having a cylinder, open at its outer end, a rotatable disk-like stop in said cylinder and extending outwardly through the passageway formed by the annular flange, a bead on the disklike stop engageable with the inner side of the flange as a stop, the disk-like stop having on its inner side ay shank axially aligned therewith, and extending axially in the cylinder, a radial ball bearing supporting the disk-like stop and its shank in the cylinder, and a thrust ball bearing between the shank on the disk-like stop and the head.

KARL FELLROTH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,608,669 Prydz Nov. 30, 1926 1,821,331 Svenson Sept. 1, 1931 2,065,083 Lovely Dec. 22, 1936 2,465,558 Toth Mar, 29, 1949 

